Weber County · about 9,100

Washington Terrace

Detached permitted on 11,000 sf lots

Ordinance 26-04, adopted unanimously on September 15, 2026, repealed and re-enacted §17.48.030. A detached unit is a permitted use on a lot of at least 11,000 square feet with a primary dwelling in an eligible residential zone. The older statement that external units are not allowed is out of date.

Internal ADU: Permitted in an eligible residential zone, inside the primary dwelling, on a lot larger than 6,000 square feet. One extra on-site stall, kept for the unit. Not in a mobile home. The city may require a separate meter.
Detached ADU: Permitted. Prohibited under 11,000 square feet. It must sit behind the front of the house and behind the front-yard setback, and it uses the accessory-building setbacks of the zone. It may not be larger in floor area than the primary dwelling, and it may not sit in an easement or the front yard.
Lot: 11,000 square feet or larger for a detached unit. Internal units are not allowed on a lot of 6,000 square feet or less. One type of ADU per lot — internal or detached, not both.
Size: The ordinance does not set a numeric floor area of its own, other than “not larger than the primary dwelling,” plus the zone’s size, height, and coverage rules. The building official told the council that 650 square feet was the smallest detached unit intended. That figure is not in the ordinance text we read. Confirm it.
Parking: Two stalls, assigned only to the unit, if it is 650 square feet or larger; one stall if it is smaller. Replace any garage or carport stall the unit takes.
Owner occupancy: The owner of record lives in the house or the unit as their principal residence. Permits, a business license, and the city’s Good Landlord program are required. The unit stays in the same ownership and cannot be split onto its own parcel.
Rental: No short-term rental. The ordinance defines that as fewer than 30 consecutive days.
Design: Compatible materials, roof form, or proportions with the house — the ordinance says the state’s design-element limit is not presumed to apply, which is a legal position to confirm, not a reason to ignore the written standard. Utilities must have capacity. The city would rather tie the unit to the house than cut a new lateral.

Notes

Source: Ordinance 26-04 and the September 15, 2026 minutes (5–0). The packet text still had blank date lines; the minutes record the vote.

A legal nonconforming duplex in a single-family zone was described by staff as ineligible. Confirm the dwelling is a permitted single-family house.

Statewide floor

Senate Bill 284, Utah Code §10-21-304, has been in effect since October 1, 2026. Every city on this list must allow a detached ADU as a permitted use — not a conditional use — on a lot of 11,000 square feet or larger that already has a permitted single-family house. A city may also allow one on a smaller lot. It may still set size, height, coverage, setbacks, and owner occupancy, and it may require that the unit not be larger than the house, not sit in the front yard, and not be rented for fewer than 90 days. Parking may not exceed one stall under 650 square feet, or two stalls at 650 square feet and above. A printed ban, or a conditional-use requirement, on a qualifying lot conflicts with the statute even if the code book is late. Confirm the city’s ordinance before anyone draws.

Inquire about a lot in Washington Terrace

We verify the ordinance that applies to your parcel as part of feasibility. Washington Terrace City